Graphical glitches with Preview mode on

I am getting some graphical glitching when using the Preview mode switch.
It seems to be where the lines/edges would normally be.

I have attached an annotated screenshot for reference.

Unsure if there is some setting I can adjust to remove the glitching or if it might be a bug?

EDIT: Interesting point I have noted is that when enabling BackFace Culling, this glitchyness doesn't seem to be there (on the Sphere I tested anyway).

EDIT 2: Another interesting point, if I disable Anti-Aliasing from the View -> Anti-Aliasing Enabled menu item I do not see this glitching either. I think this might be a bug rather than a simple setting I can adjust.

It does not happen on my side. May be a graphics card thing.